Predictors and Prevalence of Persistent Pain after Total Knee Arthroplasty in One-Year Follow-up.

Abstract

Background: Total knee arthroplasty (TKA) is one of the most common surgeries performed to reduce pain and disability in knee arthritis. Comprehension of the etiology and prevalence of persistent postoperative knee pain can help reduce this pain and identify the predictive factors leading to it. This study aimed to investigate the predictive factors and the prevalence of persistent pain after total knee arthroplasty in one-year follow-up.

Materials and methods: This was a prospective cohort study. Demographic data including age, sex, body mass index (BMI), hospital anxiety and depression scale (HADS), and comorbidities were collected. In 242 patients, preoperative and postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were measured before and immediately after surgery and in 3-, 6-, and 12-month intervals during follow-up. Loosening of the prosthesis was also investigated by radiographic imaging in every postoperative visit.

Result: WOMAC pain decreased from a mean (standard deviation) of 49 before surgery to 18 at 6 months and 13 at 12 months. Despite this, the prevalence of moderate-to-severe persistent postoperative pain (PPP) was 13.22% (n = 32) and 9.09% (n = 22) at 6 and 12 months lower preoperative WOMAC (odd's ratio:2.8), loosening of the prosthesis (odd's ratio:1.9), higher HADS (odd's ratio:2.1) were main predictors for PPP in TKA patients as in rheumatoid arthritis (odd's ratio:1.2).

Conclusion: Loosening of the prosthesis and higher preoperative WOMAC scores are key factors in persistent post-TKA pain. Depression and anxiety are more popular among patients with more pain after TKA. RA is more prevalent in patients with PPP after TKA.